Graphite electrode yog kub resistant graphite conductive khoom tsim los ntawm roj av knead, koob coke li aggregate thiab thee bitumen li binder, uas yog tsim los ntawm ib tug series ntawm cov txheej txheem xws li kneading, molding, roasting, impregnation, graphitization thiab mechanical processing. khoom.
Cov graphite electrode yog ib qho tseem ceeb ntawm high-temperature conductive khoom rau hluav taws xob steelmaking. Lub graphite electrode yog siv los nkag rau hluav taws xob hluav taws xob rau hluav taws xob rau hluav taws xob, thiab qhov kub siab uas tsim los ntawm qhov chaw nruab nrab ntawm cov electrode kawg thiab tus nqi yog siv los ua qhov cua sov kom yaj cov nqi rau cov hlau ua. Lwm cov ore furnaces uas smelt cov ntaub ntawv xws li daj phosphorus, industrial silicon, thiab abrasives kuj siv graphite electrodes ua cov ntaub ntawv conductive. Qhov zoo tshaj plaws thiab tshwj xeeb ntawm lub cev thiab tshuaj lom neeg ntawm graphite electrodes kuj tau siv dav hauv lwm qhov chaw lag luam.
Cov khoom siv raw rau kev tsim cov graphite electrodes yog roj av coke, koob coke thiab thee tar pitch.
Petroleum coke yog cov khoom siv hluav taws xob uas tau txais los ntawm coking thee residue thiab petroleum pitch. Cov xim yog xim dub thiab ntxeem tau, lub ntsiab tseem ceeb yog carbon, thiab cov ntsiab lus tshauv tsawg heev, feem ntau qis dua 0.5%. Petroleum coke belongs rau chav kawm ntawm graphitized yooj yim carbon. Petroleum coke muaj ntau yam kev siv hauv kev lag luam chemical thiab metallurgical. Nws yog cov khoom siv tseem ceeb rau kev tsim cov khoom siv graphite thiab cov khoom siv carbon rau electrolytic aluminium.
Cov roj av coke tuaj yeem muab faib ua ob hom: coke nyoos thiab calcined coke raws li kev kho cua sov. Lub qub roj av coke tau los ntawm ncua coking muaj ib tug loj npaum li cas ntawm volatiles, thiab cov neeg kho tshuab lub zog yog tsawg. Lub calcined coke yog tau los ntawm calcination ntawm raw coke. Feem ntau cov refineries nyob rau hauv Tuam Tshoj tsuas yog tsim coke, thiab calcination ua hauj lwm feem ntau yog ua nyob rau hauv cov nroj tsuag carbon.
Petroleum coke tuaj yeem muab faib ua cov coke siab sulfur (muaj ntau dua 1.5% sulfur), nruab nrab sulfur coke (muaj 0.5% -1.5% sulfur), thiab qis sulfur coke (muaj tsawg dua 0.5% sulfur). Kev tsim cov graphite electrodes thiab lwm yam khoom siv graphite feem ntau yog tsim los siv cov coke uas tsis muaj sulfur.
Koob coke yog ib hom zoo coke nrog pom tseeb fibrous kev ntxhib los mos, tsis tshua muaj thermal expansion coefficient thiab yooj yim graphitization. Thaum cov coke tawg lawm, nws tuaj yeem muab faib ua cov strips me me raws li kev ntxhib los mos (qhov sib piv feem ntau yog siab dua 1.75). Ib qho anisotropic fibrous qauv tuaj yeem pom nyob rau hauv lub tshuab ntsuas polarizing, thiab yog li hu ua rab koob coke.
Lub anisotropy ntawm physico-mechanical zog ntawm koob coke yog pom tseeb heev. Nws muaj cov hluav taws xob zoo thiab thermal conductivity sib npaug rau qhov ntev axis kev taw qhia ntawm cov khoom, thiab cov coefficient ntawm thermal expansion yog tsawg. Thaum extrusion molding, ntev axis ntawm feem ntau hais yog teem nyob rau hauv lub extrusion kev taw qhia. Yog li, koob coke yog cov khoom siv tseem ceeb rau kev tsim hluav taws xob siab lossis ultra-high-power graphite electrodes. Cov graphite electrode uas ua tau muaj qhov tsis muaj zog, me me thermal expansion coefficient thiab zoo thermal shock kuj.
Needle coke yog muab faib ua roj-raws li koob coke ua los ntawm roj av residue thiab thee-based koob coke ua los ntawm refined thee pitch raw khoom.
Coal tar yog ib qho ntawm cov khoom tseem ceeb ntawm thee tar sib sib zog nqus ua. Nws yog ib tug sib tov ntawm ntau yam hydrocarbons, dub nyob rau hauv high kub, semi-khoom los yog khoom ntawm high kub, tsis ruaj melting point, softened tom qab cua sov, thiab ces melted, nrog ib tug ceev ntawm 1.25-1.35 g / cm3. Raws li nws cov ntsiab lus softening, nws muab faib ua qhov kub thiab txias, nruab nrab kub thiab kub asphalt. Qhov nruab nrab kub asphalt tawm los yog 54-56% ntawm cov thee tar. Qhov sib xyaw ntawm thee tar yog qhov nyuaj heev, uas muaj feem xyuam rau cov khoom ntawm thee tar thiab cov ntsiab lus ntawm heteroatoms, thiab tseem cuam tshuam los ntawm cov txheej txheem coking thiab coal tar ua tej yam kev mob. Muaj ntau cov cim qhia rau tus cwj pwm thee tar suab, xws li bitumen softening point, toluene insolubles (TI), quinoline insolubles (QI), coking values, thiab thee pitch rheology.
Coal tar yog siv los ua ib qho kev khi thiab impregnant hauv kev lag luam carbon, thiab nws qhov kev ua tau zoo muaj kev cuam tshuam zoo rau cov txheej txheem tsim khoom thiab cov khoom zoo ntawm cov khoom siv carbon. Lub binder asphalt feem ntau siv qhov nruab nrab-kub lossis nruab nrab-kub hloov asphalt uas muaj qhov nruab nrab softening point, tus nqi coking siab, thiab siab β resin. Tus neeg sawv cev impregnating yog qhov nruab nrab kub asphalt uas muaj qhov muag muag qis, qis QI, thiab cov khoom zoo rheological.
Cov duab hauv qab no qhia txog cov txheej txheem tsim khoom ntawm graphite electrode hauv cov lag luam carbon.
Calcination: Cov khoom siv carbonaceous yog cua sov-kho ntawm qhov kub siab kom tso tawm cov dej noo thiab cov teeb meem tsis zoo nyob rau hauv, thiab cov txheej txheem tsim khoom sib raug rau kev txhim kho ntawm qhov kev ua noj ua haus thawj zaug hu ua calcination. Feem ntau, carbonaceous raw khoom yog calcined los ntawm kev siv roj thiab nws tus kheej volatiles raws li ib tug kub qhov chaw, thiab qhov siab tshaj plaws kub yog 1250-1350 ° C.
Calcination ua rau muaj kev hloov pauv loj hauv cov qauv thiab cov khoom siv lub cev ntawm cov ntaub ntawv carbonaceous, feem ntau hauv kev txhim kho qhov ntom ntom, txhua yam muaj zog thiab hluav taws xob conductivity ntawm coke, txhim kho cov tshuaj stability thiab oxidation tsis kam ntawm coke, nteg lub hauv paus rau cov txheej txheem tom ntej. .
Cov khoom siv Calcined feem ntau suav nrog tank calciner, rotary kiln thiab hluav taws xob calciner. Qhov kev tswj xyuas zoo ntawm calcination yog qhov tseeb qhov ceev ntawm roj av coke tsis tsawg dua 2.07g / cm3, qhov resistivity tsis ntau tshaj 550μΩ.m, qhov tseeb ntom ntawm koob coke tsis tsawg dua 2.12g / cm3, thiab resistivity tsis ntau tshaj 500μΩ.m.
Raw khoom crushing thiab cov khoom xyaw
Ua ntej batching, bulk calcined petroleum coke thiab koob coke yuav tsum tau crushed, av, thiab sieved.
Qhov nruab nrab crushing feem ntau yog ua los ntawm cov cuab yeej crushing ntawm li 50 hli los ntawm lub puab tsaig crusher, rauj crusher, yob crusher thiab cov zoo li mus ntxiv crushing 0.5-20 hli loj cov khoom xav tau rau batching.
Milling yog txheej txheem ntawm kev sib tsoo cov khoom siv carbonaceous rau cov hmoov me me ntawm 0.15 hli lossis tsawg dua thiab qhov loj me ntawm 0.075 hli los yog tsawg dua los ntawm kev ncua-hom nplhaib yob zeb (Raymond zeb), pob zeb, lossis lwm yam. .
Kev tshuaj ntsuam xyuas yog txheej txheem uas muaj ntau yam khoom siv tom qab kev sib tsoo tau muab faib ua ntau qhov sib txawv me me nrog rau qhov nqaim ntawm qhov ntau thiab tsawg los ntawm ntau cov sieves nrog cov qhib sib xws. Tam sim no electrode ntau lawm feem ntau xav tau 4-5 pellets thiab 1-2 hmoov qib.
Cov khoom xyaw yog cov txheej txheem ntau lawm rau kev suav, ntsuas thiab tsom mus rau ntau yam kev sib sau ua ke ntawm cov khoom sib xyaw thiab cov hmoov thiab cov binders raws li cov qauv tsim. Kev tsim nyog ntawm kev tsim thiab kev ruaj ntseg ntawm kev ua haujlwm batching yog ib qho tseem ceeb tshaj plaws uas cuam tshuam rau qhov ntsuas qhov zoo thiab kev ua haujlwm ntawm cov khoom.
Tus qauv yuav tsum txiav txim siab 5 yam:
1 Xaiv cov khoom siv raw;
2 txiav txim qhov feem ntawm ntau hom raw khoom;
3 txiav txim qhov loj me me ntawm cov khoom raw khoom;
4 txiav txim siab tus nqi ntawm binder;
5 Txiav txim seb hom thiab tus nqi ntawm cov khoom ntxiv.
Kneading: Sib tov thiab quantifying ntau yam me me carbonaceous granules thiab hmoov nrog ib tug npaum li cas ntawm binder ntawm ib tug tej yam kub, thiab kneading lub plasticity paste rau hauv ib tug txheej txheem hu ua kneading.
Kneading txheej txheem: qhuav mixing (20-35 min) ntub mixing (40-55 min)
Lub luag haujlwm ntawm kneading:
1 Thaum sib tov qhuav, ntau yam khoom siv raw yog sib xyaw ua ke, thiab cov khoom siv carbonaceous ntawm cov khoom sib txawv ntawm qhov sib txawv yog sib xyaw ua ke thiab ua kom zoo dua qhov sib xyaw ntawm qhov sib tov;
2 Tom qab ntxiv cov thee tar pitch, cov khoom qhuav thiab cov asphalt yog sib xyaw ua ke. Cov kua asphalt uniformly coats thiab ntub rau saum npoo ntawm cov granules los ua ib txheej ntawm asphalt bonding txheej, thiab tag nrho cov ntaub ntawv raug sib raug zoo rau ib leeg los ua ib homogeneous yas smear. Yooj yim rau molding;
3 qhov chaw ntawm cov thee tar pitch nkag mus rau hauv qhov chaw sab hauv ntawm cov khoom siv carbonaceous, ntxiv rau qhov ceev thiab cohesiveness ntawm cov muab tshuaj txhuam.
Moulding: Lub molding ntawm cov khoom siv carbon yog hais txog cov txheej txheem ntawm plastically deforming lub kneaded carbon paste nyob rau hauv lub sab nraud quab yuam siv los ntawm cov khoom molding thaum kawg tsim ib lub cev ntsuab (los yog raw khoom) muaj ib tug tej yam zoo li, loj, ceev thiab lub zog. txheej txheem.
Hom molding, khoom siv thiab cov khoom tsim:
Txoj kev molding
Cov cuab yeej siv
cov khoom tseem ceeb
Moulding
Vertical hydraulic xovxwm
Hluav taws xob carbon, low-grade zoo qauv graphite
Nyem
Kab rov tav hydraulic extruder
Ntsia hlau extruder
Graphite electrode, square electrode
Kev vibration molding
Vibration molding tshuab
Aluminium carbon cib, blast furnace carbon cib
Isostatic nias
Isostatic molding tshuab
Isotropic graphite, anisotropic graphite
Squeeze kev ua haujlwm
1 Cov khoom siv txias: cov khoom siv txias txias, cov khoom siv lub tog raj kheej txias, sib tov thiab kneading cov khoom cua txias, thiab lwm yam.
Tshem tawm cov volatiles, txo kom haum rau qhov kub thiab txias (90-120 ° C) kom cov adhesion, kom lub blockiness ntawm paste yog uniform rau 20-30 min.
2 Chaw thau khoom: nias nqa baffle —- 2-3 zaug txiav —-4-10MPa compaction
3 pre-pressure: siab 20-25MPa, lub sij hawm 3-5min, thaum lub tshuab nqus tsev
4 extrusion: nias down lub baffle -5-15MPa extrusion - txiav - rau hauv lub dab dej txias
Technical parameters ntawm extrusion: compression piv, xovxwm chamber thiab nozzle kub, txias kub, preload siab lub sij hawm, extrusion siab, extrusion ceev, txias dej kub
Kev tshuaj xyuas lub cev ntsuab: bulk ntom, zoo li tapping, tsom xam
Calcination: Nws yog txheej txheem uas cov khoom siv roj carbon lub cev ntsuab tau ntim rau hauv lub tshuab cua sov tshwj xeeb hauv qab kev tiv thaiv ntawm cov muab tub lim los ua cov txheej txheem kub kub kom carbonize thee suab hauv lub cev ntsuab. Lub bitumen coke tsim tom qab cov carbonization ntawm cov thee bitumen solidifies cov carbonaceous aggregate thiab cov hmoov hais ua ke, thiab cov calcined carbon cov khoom muaj siab mechanical zog, tsis tshua muaj hluav taws xob resistivity, zoo thermal stability thiab tshuaj stability. .
Calcination yog ib qho ntawm cov txheej txheem tseem ceeb hauv kev tsim cov khoom siv carbon, thiab tseem yog ib feem tseem ceeb ntawm peb txoj kev kho cua sov loj ntawm graphite electrode ntau lawm. Lub voj voog ntau lawm ntawm calcination yog ntev (22-30 hnub rau ci, 5-20 hnub rau qhov cub rau 2 ci), thiab siab zog noj. Qhov zoo ntawm ntsuab roasting muaj feem xyuam rau qhov zoo ntawm cov khoom tiav thiab cov nqi ntawm cov khoom.
Cov pob zeb ntsuab hauv lub cev ntsuab yog coked thaum lub sijhawm ci, thiab kwv yees li 10% ntawm cov teeb meem tsis hloov pauv, thiab qhov ntim yog tsim los ntawm 2-3% shrinkage, thiab qhov poob loj yog 8-10%. Lub cev thiab tshuaj lom neeg cov khoom ntawm cov pa roj carbon billet kuj hloov pauv loj. Qhov porosity poob ntawm 1.70 g / cm3 mus rau 1.60 g / cm3 thiab cov resistivity poob ntawm 10000 μΩ·m mus rau 40-50 μΩ·m vim qhov nce ntawm porosity. Lub zog txhua yam ntawm calcined billet kuj loj. Rau kev txhim kho.
Qhov thib ob ci ci yog txheej txheem uas cov khoom calcined yog immersed thiab ces calcined kom carbonize lub suab rau hauv lub pores ntawm cov khoom calcined. Cov hluav taws xob uas yuav tsum tau ntau dua cov tuab tuab (txhua hom muaj kev sib koom ua ke, thiab cov ntawv sib xyaw yuav tsum tau raug muab cov kab ntawv sib xyaw, thiab cov pob qij txha yog tseem muaj rau peb-dip plaub-ci.
Lub ntsiab rauv hom roaster:
Kev ua haujlwm tsis tu ncua - - nplhaib rauv (nrog npog, tsis muaj npog), qhov cub
Kev ua haujlwm tsis sib xws—-rov qab kiln, hauv pem teb roaster, lub thawv roaster
Calcination nkhaus thiab qhov kub siab tshaj plaws:
Ci ib zaug - 320, 360, 422, 480 teev, 1250 ° C
Secondary roasting - 125, 240, 280 teev, 700-800 ° C
Kev tshuaj xyuas cov khoom ci: zoo li tapping, hluav taws xob tiv thaiv, qhov ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntu
Impregnation yog txheej txheem uas cov khoom siv carbon muab tso rau hauv lub nkoj siab thiab cov kua impregnant pitch yog immersed nyob rau hauv lub pores ntawm cov khoom electrode nyob rau hauv tej yam kub thiab siab tej yam kev mob. Lub hom phiaj yog txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau cov khoom lag luam, ua kom muaj zog thiab cov tshuab ua kom muaj zog ntawm cov khoom lag luam, thiab txhim kho hluav taws xob thiab thermal conductivity ntawm cov khoom.
Cov txheej txheem impregnation thiab lwm yam kev tsis sib xws yog: roasting billet - deg tu - preheating (260-380 ° C, 6-10 teev) - loading lub impregnation tank - nqus tsev vacuuming (8-9KPa, 40-50min) - txhaj tshuaj bitumen (180) -200 ° C) - Pressurization (1.2-1.5 MPa, 3-4 teev) - Rov qab mus rau asphalt - txias (sab hauv lossis sab nraum lub tank)
Kev tshuaj xyuas cov khoom impregnated: impregnation hnyav nce tus nqi G = (W2-W1) / W1 × 100%
Ib qho dipping hnyav nce tus nqi ≥14%
Secondary impregnated khoom hnyav nce tus nqi ≥ 9%
Peb dipping khoom hnyav nce tus nqi ≥ 5%
Graphitization yog hais txog cov txheej txheem kev kho cua kub kub uas cov khoom siv roj tau ua kom sov rau qhov kub ntawm 2300 ° C los yog ntau tshaj nyob rau hauv ib qho kev tiv thaiv nruab nrab nyob rau hauv high-temperature hluav taws xob rauv los hloov cov amorphous txheej txheej carbon rau hauv peb-dimensional xaj. graphite siv lead ua qauv.
Lub hom phiaj thiab cov nyhuv ntawm graphitization:
1 txhim kho cov conductivity thiab thermal conductivity ntawm cov khoom siv carbon (cov resistivity yog txo los ntawm 4-5 zaug, thiab thermal conductivity yog nce li ntawm 10 npaug);
2 txhim kho cov thermal shock kuj thiab tshuaj stability ntawm cov khoom siv carbon (linear expansion coefficient txo los ntawm 50-80%);
3 los ua kom cov khoom siv roj carbon lubrication thiab abrasion tsis kam;
4 Tshem tawm impurities, txhim kho cov purity ntawm cov khoom siv carbon (cov hmoov tshauv ntawm cov khoom raug txo los ntawm 0.5-0.8% mus txog 0.3%).
Lub realization ntawm graphitization txheej txheem:
Lub graphitization ntawm cov khoom siv carbon yog nqa tawm ntawm qhov kub ntawm 2300-3000 ° C, yog li nws tsuas tuaj yeem pom tau los ntawm hluav taws xob cua sov hauv kev lag luam, uas yog, tam sim no ncaj qha dhau los ntawm cov khoom siv calcined, thiab cov khoom calcined raug them. rau hauv lub cub tawg yog tsim los ntawm cov hluav taws xob tam sim no ntawm qhov kub thiab txias. Tus neeg xyuas pib dua yog ib yam khoom uas tau rhuab mus rau qhov kub thiab txias.
Furnaces tam sim no dav siv xws li Acheson graphitization furnaces thiab internal heat cascade (LWG) furnaces. Lub qub muaj cov zis loj, qhov sib txawv ntawm qhov kub thiab txias, thiab kev siv hluav taws xob ntau. Cov tom kawg muaj lub sijhawm cua sov luv, tsis siv hluav taws xob tsawg, cov hluav taws xob tsis sib xws, thiab tsis haum rau kev haum.
Kev tswj ntawm cov txheej txheem graphitization yog tswj los ntawm kev ntsuas lub zog hluav taws xob nkhaus uas haum rau qhov kub thiab txias. Lub sijhawm siv hluav taws xob yog 50-80 teev rau Acheson rauv thiab 9-15 teev rau LWG rauv.
Kev siv hluav taws xob ntawm graphitization yog qhov loj heev, feem ntau 3200-4800KWh, thiab tus nqi ntawm cov txheej txheem suav txog li 20-35% ntawm tag nrho cov nqi tsim khoom.
Kev tshuaj xyuas ntawm cov khoom siv graphitized: zoo li tapping, ntsuas kev tiv thaiv
Machining: Lub hom phiaj ntawm kev siv tshuab machining ntawm cov khoom siv roj carbon graphite yog ua kom tiav qhov loj me, cov duab, precision, thiab lwm yam los ntawm kev txiav kom ua rau lub cev electrode thiab cov pob qij txha raws li cov kev xav tau ntawm kev siv.
Graphite electrode ua tau muab faib ua ob txoj kev ua haujlwm ywj pheej: electrode lub cev thiab sib koom ua ke.
Lub cev ua haujlwm suav nrog peb kauj ruam ntawm kev tho txawv thiab ntxhib tiaj tiaj lub ntsej muag, lub voj voog sab nrauv thiab lub ntsej muag tiaj tus thiab milling xov. Kev ua tiav ntawm conical sib koom ua ke tuaj yeem muab faib ua 6 txheej txheem: txiav, lub ntsej muag lub ntsej muag lub ntsej muag, lub ntsej muag lub ntsej muag lub tsheb, milling xov, drilling bolt Thiab slotting.
Kev sib txuas ntawm electrode pob qij txha: conical sib txuas (peb buckles thiab ib lub buckle), cylindrical sib txuas, pob sib txuas (txiv neej thiab poj niam kev sib txuas)
Kev tswj ntawm machining raug: xov taper sib txawv, xov suab, sib koom ua ke (lub qhov) loj txoj kab uas hla sib txawv, sib koom lub qhov coaxiality, sib koom lub qhov verticality, electrode kawg lub ntsej muag flatness, sib koom plaub-point deviation. Tshawb xyuas nrog cov nplhaib tshwj xeeb thiab cov phaj ntsuas.
Kev kuaj xyuas cov ntawv sau tiav: Qhov hnyav, qhov hnyav, diam, tsis ntom, ua ntej ua ntej yuav thev taus, thiab lwm yam.
Post lub sij hawm: Oct-31-2019